Well drilling bit



Aug. 23, 1932. 1 Q WRlGHT y 1,873,240

WELL DRILLING BIT Filed Aug. 9, 1929 I I I I I I I I /0 I I l I f2 I l 1. I I I I l I I I I j? j A- J? 37 7 i? 7 J2, J2

.if J6 J2 J6 J6 J6 J* *3 JZ Patented Aug. 23, 1932 UNITED STATES PATENT OFFICE w JESSE C.

WRIGHT, F LOS ANGELES, CALIFORNIA, ASSIGNOR TO GLOBE OIL TOOLS C0.,

0F LOS NIETOS, CALIFORNIA, A CORPORATION OF CALIFORNIA WELL DRILLING BI'I Application led August 9, 1929. Serial No. 384,618.

This invention has to do with a well drilling bit, and it is a general object of the invention to provide a simple, effective and improved bit of the type which operates to make an g5, annular cut and then remove the formation or core left by the annular cut.

It is a general object of the present invention to provide a simple, effective and economical construction for uniting a shank and lo cutter head so that the head is securely and dependably connected to the shank and can be detached therefrom for purpose of repair or replacement.

A further object of the invention is to prole vide an improved formation of cutter head for application to a shank in which the cutting parts are related so that they are particularly effective in penetrating the formation being drilled and in drilling a straight 30 hole.

It is another object of the invention to provide a bit of the character mentioned in which the cutter head is provided with reaming blades related to the cutting teeth at the forward end of the bit to maintain the hole to gauge and steady the bit so that it operates smoothly and drills a straight hole.

Another object of the invention is to provide a simple, dependable and inexpensive construction for securing a cutter head to a shank.

The various objects and features of my invention will be best and more fully understood from the following detailed description of a typical form and application of the invention, throughout which description reference is had to the accompanying drawing, in which:

Fig. 1 is a side elevation of a typical well drillin bit embodying the present invention. indicated by line 2--2 of Fig. 1. Fig. 3 is a bottom end view of the bit, being a view taken as indicated by line 3-3 on Fig. 1, and Fig. 4 is a detailed plan section taken as indicated by line 4-4 on Fig. 1.

The bit provided by this invention is of the drag or tooth type and includes a shank and a head detachable from the shank, the head having cutting parts operating to make lower end portion of the shank is yoked ig. 2 is a view of the bit taken as an annular cut in the formation, to remove the core left standing upon the annular cut being made, and to ream the bore to the desired gauge. The bit includes, generally, a shank and a cutter head 11 to be mounted 5 at the lower endof the shank.

The shank l0 includes, generally, a main part or stem 12 provided at its upper end with a tapered screw-threaded pin projection 13 for connecting the bit with a drilling string and having an enlarged lower end portion which carries the head 11. ThJ

an formed so that it has two flat side parts 14 with a socket 15 between them/the socket 15 extending upwardly from the lower end of the shank and across the enlarged part of the shank. It is to be noted that the lower end portion of the shank is widened in the direction of the socket 15 so that the wide' parts 14 are considerably wider than the stem portion 12 of the shank. The lower ends 1G of the side parts 14 are flattened to form an abutment for the cutter head, while the outer edges or corners 17 of the parts 14 are dressed or bevelled away as illustrated throughout the drawing. Further, the edges or corners 18 of the lower end portions of the parts 14 may be bevelled or dressed away as shown in the drawing. The shank has a circulation opening 19 extending downwardly into it from its upper end and has discharge openings 2O in its lower end portion communicating with the opening 19 and discharging at the bevelled corners 18 to direct circulation iuid to the cutting parts of the cutter head 11.

The cutter head 11 is in the form of a unit adapted to be attached to the lower end portion of the shank 10 and includes, generally, a body part adapted to engage the lower ends 16 of the shank parts 14, a rib or tiange 31 projecting from the body part to extend into the socket 15 of the shank, out-er teeth 32 and 33 projecting downwardly from the outer end portions of the body 30, roaming cutters 34 on the flange 31, and inner cutters 35 arranged to destroy the core left standing by the cutters 32 and 33.

The body part 30 of the cutter head extends across or along the lower end portion 100 tings.

of the shank to cover the ends 16 of the shank parts 14. The flange 31 extends upwardly from the body part and is shaped to fit the socket 15 in the manner illustrated in the drawing. In the preferred construction the end portions of the socket 15 are enlarged as at and the flange 31 has vertical ribs 51 fitting the enlargements of the socket. By this construction the flange 31 is braced in the socket so that it cannot shift laterally of the axis of the tool. Further, this construction reinforces the flange 31 and the reaming parts 34 about to be described. The flange 31 is secured or held in the socket by two bolts 40 which extend between the side parts 14 of the shank and through openings 41 provided in the flange 31. The ends of the bolts 40 are preferably countersunk in the parts 14 so that they do not project from the shank in a manner to interfere with the free circulation of circulating fluid or cut- The flange 31 projects beyond the socket 15 at opposite sides of the shank, forming the reaming cutters 34. The forward vertical edges 43 of the projecting fiange parts are sharpened to form reaming edges.

The teeth, which project downwardly from the body part 30 of the cutter head to make an annular cut in the formation being drilled, are arranged in two groups located diametrically opposite each other, each group including a forward tooth 32 and a rear tooth 33. The teeth 32 and 33 of each group are located so that the forward tooth 32 is somewhat ahead of one of the reaming edges 43, while the rear tooth 33V is somewhat behind the said reaming edge 43. This relationing of parts is clearly illustrated in Fig. 4 of the drawing. .The teeth 32 and`33 pro- .ject downward and forward from the endl cutting edges are substantially radial with Ain the drawing.

reference to the central axis of the bit, as shown in the drawing.

The inner cutters 35 provided to remove the core left standing by the teeth 32 and 33 are preferably in the form of stepped `blades extending upwardly land inwardly myself to the specific details set forth, but wish to reserve to myself any changes or variations that may appear to those skilled ,in the art or fall within the scope of the following claim:

Having described my invention, I claim:

A bit of the character described including, a shank having a bifurcated lower end forming a socket of uniform width across substantially the entire Width of the shank, the socket being enlarged at its opposite ends, a cutter head having downwardly projecting teeth and a flange extending into and closely fitting the socket, the flange having enlarged parts extending along its opposite ends itting the enlarged ends of the socket to hold the flange against horizontal movement in the socket and having projecting end parts forming reamer cutters, and a. bolt extending through both port-ions of the bifurcated end of the shank and the fiange for holding the flange in the socket, the ends of the bolt being countersunk in the shank.

In Witness that I claim the foregoing I have hereunto subscribed my name this 11th day of July, 1929.

, v JESSE C. WRIGHT.

from the forward cutters 32 to the central .l

portion of the bit. In the preferred arrangement there are two inner blades 35 located diametrically opposite each other and Vjoining theforward teeth 32, as clearlyshown Having described only a typical, preferred form ofmy invention, I do not wish.v yto limit= l Iso 

